| 摘要 |
PURPOSE:To permit increase of duty at the medium speed of the engine rpm by providing a duty control circuit, which can be suitably produced as a monosilic IC. CONSTITUTION:An ignition timing signal produced with the rotation of the engine is coupled through resistors 5 and 6 to the base of a first-stage transistor 30 of an amplifier circuit. A series diode circuit consisting of two diodes 16 and 17 and a diode 19 in parallel with the series circuit are provided between the base of the transistor 30 and earth. A series circuit consisting of a capacitor 2 and a resistor 8 is provided in parallel with the resistor 7. The juncture between the resistors 16 and 17 is connected to the juncture between the resistor 8 and capacitor 2. Current is supplied from a power supply through a resistor 14 to the Q terminal of a pick-up coil 1. Increase of duty is determined by the capacitance of the capacitor 2 and the time constant of the discharging circuit of the capacitor 2. |
